Attachment is an emotional bond and connection to another person. Psychologist John Bowlby was the first attachment theorist, describing attachment as a "lasting psychological connectedness between human beings" (Bowlby, 1969, p. 194).

Bowlby believed that the earliest bonds formed by children with their caregivers have a tremendous impact that lasts throughout life. According to Bowlby, attachment also serves to keep the infant close to the mother, thus improving the child's chances of ‘survival’.